Valves for pressure reduction are known as pressure reducers from the state of the art and are used for monitoring.
A respiration drive is designed in GB 2324122 B2 in the form of a radial flow compressor rotating at a high rpm. The respiration drive acts as a pressure source, which makes available a pressure rising with increasing rpm. Thus, the variation of the rpm is a manipulated variable for adapting the respiration pressure to the respiration situation, which means that the rpm must be cyclically increased and decreased again synchronously with the breathing cycle by varying the respiration pressure in such a way that the variation is resolved for individual breaths.
U.S. Pat. No. 6,877,511 BB describes a variation of the respiration pressure for the inspiration and expiration phases of a compressor, which variation is brought about by acceleration and deceleration of a rotary compressor.
In a medical gas delivery means driven electromechanically with variable air delivery capacity according to the state of the art, the particular pressure being currently delivered is brought about by varying the rpm as a function of an external actuating signal, for example, the signal of a respirator.
A medical gas delivery means driven electromechanically with variable air delivery capacity comprises in the sense of the present invention a gas delivery means, gas delivery device or gas delivery unit in an embodiment with an electromechanical blower drive, radial flow compressor, rotary compressor, or side channel compressor.
These variations of the rpm lead to accelerations and deceleration operations. The accelerations and decelerations of radial flow compressors and/or rotary compressors, which occur in a cumulative manner during the life of the product, impose very high requirements on temperature and media resistance, reliability and low wear for the components present in the device, such as shafts, bearings and seals, based on the intended use for supplying patients with clean breathing air. These requirements cannot be guaranteed in each application over the entire life of the product, so that some components must undergo maintenance or be replaced at certain time intervals.
If the electromechanically driven medical gas delivery means is not operated variably but without being affected by an external actuating signal, the electromechanically driven medical gas delivery means must be operated permanently at the maximum necessary pressure level, even in the case in which the medical device being supplied does not continuously call for this pressure level for respirating a patient or the outlet of the electromechanically driven medical gas delivery means is blocked from time to time by closed valves in the respirator.
Reliable self-cooling by the air stream being delivered is thus no longer available. The self-cooling by the air stream is essential especially if the radial flow compressor or rotary compressor is encapsulated in a housing part to achieve reduced noise generation. The temperature rise resulting herefrom leads to a thermal load for the components such as shafts, bearings and seals. Operation of the electromechanically driven medical gas delivery means without self-cooling is therefore disadvantageous with respect to the service life both for operation with and without variation of the rpm. An essential percentage of the wear is due to thermal load and to dynamic accelerations and deceleration operations brought about by the respiration control.